Objectives: The object of this project is to produce a visual record and analysis of the "killing" of chicken red blood cells (targets) by P388D1 mouse leukemia cells (effectors). Major findings: Preliminary results of microcinematographic studies of P388D1-chicken red cell antibody dependent cellular cytotoxicity showed that: 1) killing of red cells occurred in 0.5 to 2.0 minutes after contact was established with P388D1 cells; 2) a single P388D1 cell could kill several red cells; 3) approximately 60% of killed red cells in contact with P388D1 were phagocytized in 2 to 12 minutes after firm contact was established; 4) P388D1 cells were not killed by ingested chicken red cells, and 5) P388D1 cells killed chicken red cells in the absence of phagocytosis. Proposed course: After further analysis of film on hand and time- lapse microcinematography of "killing" of chicken red cells by P388D1 cells treated with iodoacetate, which prevents phagocytosis, data will be reviewed, after which Dr. Koren and Mr. Morgan will write a report.